(a) Field of the Invention
The present invention innovatively discloses that at least two asynchronous AC induction electrical machines (hereinafter referred to as electrical machine) in parallel connection with the power source are respectively installed with a main winding and control winding for electrical machine operation, wherein the two electrical machines are combined by a cross-interlocked parallel connection that includes the following:
The first electrical machine control winding and the first electrical machine main winding are windingly installed on the same polar axis or windingly installed at an electrical angle between polar axes within the first electrical machine, wherein the two electrical machines are optionally operated in cross-interlocked parallel connection according to operating requirements of the polarity relationship between the two electrical machines to provide: 1) additive excitation operation in the same polarities, or 2) differential excitation operation in reverse polarities;
The second electrical machine control winding and the second electrical machine main winding are windingly installed on the same polar axis or windingly installed at an electrical angle between polar axes within the second electrical machine, wherein the two electrical machines are optionally operated in cross-interlocked parallel connection according to operating requirements of the polarity relationship between the two electrical machines to provide: 1) additive excitation operation in the same polarities, or 2) differential excitation operation in reverse polarities;
The first electrical machine main winding is the main operating winding of the first electrical machine, while the first terminal of the first electrical machine control winding is connected with the second terminal of the second electrical machine main winding installed in the second electrical machine;
The second electrical machine main winding is the main operating winding of the second electrical machine, wherein the first terminal of the second electrical machine control winding is connected with the second terminal of the first electrical machine main winding installed in the first electrical machine;
The first terminal of the first electrical machine main winding is connected with the first terminal of the second electrical machine main winding and further connected to the first terminal of the power source for input or output of electric power;
The second terminal of the first electrical machine control winding is connected with the second terminal of the second electrical machine control winding and further connected to the second terminal of the power source for input or output electric power;
The windings of the first electrical machine and second electrical machine are parallel connected and are driven by the power source, wherein the operational effect of the first electrical machine and the second electrical machine being in cross-interlocked parallel connection to drive the load individually results from changes in individual electrical machine loading status to provide variable impedance operation so as to change the end voltage ratio between individual electrical machines in cross-interlocked parallel connection, thereby allowing each individual electrical machine to produce an interaction having a required electromagnetic effect.
Especially for the application of multiple asynchronous AC induction electrical machines to drive a common load, when the common load varies in an unstable fashion against loads imposed by individual asynchronous AC induction electrical machines, such as in the example of using individual asynchronous AC induction electrical machines to drive different wheels, the load at the wheels on both sides will vary accordingly when the vehicle is making a turn. In the example of a tram connecting multiple coaches to constitute a common load with individual asynchronous AC induction electrical machines disposed on individual coaches to drive the coaches individually, when the tram is speeding, decelerating or climbing up/down slopes, the common load varies according to the load imposed by the individually disposed asynchronous AC induction electrical machines, and therefore the real time response and adjustment between individual asynchronous AC induction electrical machines is very important. The conventional solution is to use individual detecting devices installed on individual asynchronous AC induction electrical machines to deliver a signal indicative of load variations to a central controller, and then to drive a control device disposed on individual asynchronous AC induction electrical machines and subject to the control of the central controller so as to control the corresponding operation performance of the individual asynchronous AC induction electrical machines. The conventional solution has the drawbacks of being a complicated system, and having lower reliability and longer response adjustment time period between individual asynchronous AC induction electrical machines, so that when applied to for example the tram connecting multiple coaches to constitute the common load as aforementioned, the individual coaches are prone to generate a jostle phenomenon;
The present invention innovatively proposes to solve these problems by providing asynchronous AC induction electrical machines in cross-interlocked parallel connection through the windings of multiple asynchronous AC induction electrical machines to thereby generate random adjustment of the operation performance according to the load variations, thereby having the advantages of simplifying the system and increasing the reliability, as well as shortening the response adjustment time period of asynchronous AC induction electrical machines to load variations so as to promote the stability of the system.
(b) Description of the Prior Art
When multiple units of conventional asynchronous AC induction electrical machines are parallel connected for motor or generator function and individually operated to drive the load, the individual electrical machines operate independently, and thereby are unable to interact to improve the overall response to load variations.